1. Field of the Invention
Embodiments of the invention generally relate to an apparatus and method for chemical mechanical polishing of substrates or wafers, more particularly, to a polishing article and a method of manufacture of a polishing article for chemical mechanical polishing.
2. Description of the Related Art
In the fabrication of integrated circuits and other electronic devices on substrates, multiple layers of conductive, semiconductive, and dielectric materials are deposited on or removed from a feature side of a substrate. The sequential deposition and removal of these materials on the substrate may cause the feature side to become non-planar and require a planarization process, generally referred to as polishing, where previously deposited material is removed from the feature side of a substrate to form a generally even, planar or level surface. The process is useful in removing undesired surface topography and surface defects, such as rough surfaces, agglomerated materials, crystal lattice damage and scratches. The polishing process is also useful in forming features on a substrate by removing excess deposited material used to fill the features and to provide an even or level surface for subsequent deposition and processing
One polishing process is known as Chemical Mechanical Polishing (CMP) where a substrate is placed in a substrate carrier assembly and controllably urged against a polishing media mounted to a moving platen assembly. The carrier assembly provides rotational movement relative to the moving platen and material removal is accomplished by chemical activity, mechanical abrasion, or a combination of chemical activity and mechanical abrasion between the feature side of the substrate and the polishing media.
CMP has advanced over the years and is essentially limited to two types of systems that differ in the type polishing media mounted to the platen assembly that contacts the feature side of the substrate. One type of polishing media is a circular stick-down pad, known in the art as conventional CMP polishing material or a standard pad that is bound to the platen by adhesives and uses a chemical composition containing small abrasive particles that is flowed onto the processing surface of the pad to provide mechanical abrasion and polish the substrate. Standard pads typically have a roughened, durable surface and are relatively thicker and less pliable than other types of polishing media. Although this thickness and relative hardness typically results in a longer usable life of the pad, the pad is eventually spent. Replacement is time consuming since the pad must be peeled off the platen, the platen must be cleaned before a new pad is installed, and requalification of the tool is required.
Another type of system is known in the art as a web system or roll format. This system typically uses a relatively pliable, web of material on the rotating platen assembly. The web type material is typically a continuous roll moved from a feed roll and advanced across the platen assembly in a rectangular section to a take-up roll. The rectangular section is adapted to contact the feature side of the substrate and the web material effects mechanical abrasion to remove material. After a number of substrates have been processed, a portion of the polishing surface is spent, and the web may be advanced in small increments at predetermined intervals, e.g., one inch or less, to provide the introduction of a new portion of polishing surface to the substrate. Once this advancement depletes the supply roll, a new supply roll is installed in a manner that takes considerably less time than circular pad replacement.
Therefore, there is a need in the art to combine the durability of a standard pad with the ease of replacement offered by a roll format, and a polishing article that is capable of providing process uniformity in a polishing surface typical of the standard pad.